A brief answer to the question, “Can dogs eat tuna fish?” is a simple, “Yes.” Dogs can have tuna, as it is not toxic to them.
In fact, tuna is even sometimes included in commercial dog foods.
But there are concerns about the level of mercury, especially as found in larger varieties of tuna.
Generally speaking, tuna is as healthy for your dog as it is for you, as long as it is given only in small amounts.
But it’s always wise to pay close attention to what makes up a healthy diet.
Can Dogs Eat Tuna?
Can dogs have tuna? Does it matter whether it is fresh or from a can?
Tuna is becoming a controversial protein source for dogs and cats because of where this large fish sits in the ocean food chain. These days, the sea is polluted with mercury, a heavy metal.
This pollution is caused by burning fossil fuels, as well as forest fires and volcanic eruptions.
Smaller fish take in mercury, and then big fish like tuna eat those smaller fish.
Tuna is both a staple of human and canine diets and one of the most potent food sources of toxic mercury levels. For this reason, feeding dogs tuna should be done with care.
There are more than 20 different species of tuna fish. Only about five of those species appear regularly on people’s plates.
These include skipjack, yellowfin, albacore, bigeye, and bluefin.
Tuna And Dogs
Can dogs eat tuna fish? To a certain extent, this could depend on the size of the tuna fish being served.
For example, the relatively small skipjack tuna weighs around 42 pounds at maturity. Contrast this with the bluefin, which can weigh a robust 1,000 pounds or more!
This is relevant because, well, you don’t even need to guess which tuna has more mercury.
The albacore tuna is the next smallest fish, weighing in at around 73 pounds at adulthood. Mature yellowfin and bigeye tuna tend to weigh in around 400 pounds.
So when feeding tuna fish for dogs, always choose skipjack or albacore tuna for a lower mercury content per serving.
Research shows that each fish has the following mercury content:
- Skipjack (“chunk light” in canned form). 0.12 parts per million.
- Albacore (“white albacore” in canned form). 0.32 parts per million.
When Is Tuna Bad For Dogs?
So is tuna safe for dogs to eat? The concern about mercury level can be worrying, and yet, tuna is sometimes used as an ingredient in commercial dog foods.
However, researchers studying this issue have released the opinion that mercury levels in commercial dog food are not currently a concern.
For further reassurance, to date, no cases of mercury poisoning from tuna in dogs have been reported.
With that in mind, it’s still best to limit the amount of tuna that you give your dog.
Of course, any dog can develop an intolerance or an allergy to any given food. So just because tuna is relatively safe for a dog to eat does not automatically mean that your dog will enjoy it.
Is Tuna Good For Dogs?
As mentioned above, tuna can be found as a source of protein in commercial dog foods. This is especially good for dogs with sensitive stomachs that don’t tolerate poultry protein well.
Protein from tuna can be greatly beneficial for a sensitive dog, helping them to get the nutrients they need without stomach upset.
Health Benefits Of Tuna For Dogs
Actually, tuna does have some potent nutritional benefits. Tuna has a high protein content and contains plenty of omega-3 fatty acids.
These are vital to healthy blood pressure, heart function and overall cardiovascular health.
Tuna also contains plenty of beneficial B vitamins, plus vitamin D, potassium, magnesium, iodine, choline, phosphorus, and selenium. About this last mineral – tuna has also been found to contain a unique type of selenium called selenoneine.
Selenoneine has a special super power – it can bind to mercury and protect cells from mercury damage! Of course, more research is needed to learn exactly how selenoneine works once tuna is consumed, but this is something interesting to keep an eye on!
In theory, tuna is good for dogs because of its high vitamin and mineral content and the presence of omega-3 fatty acids.
However, it is also true that other fish such as salmon, flounder and herring can provide similar nutritional benefits without the mercury risk.
Remember, though that dogs already get everything that they need from their kibble or canned food.
Can Dogs Eat Canned Tuna?
Canned tuna can be packed in water or in oil. But can dogs eat tuna in oil?
For that matter, can dogs eat tuna in water?
For the question, “Is canned tuna ok for dogs?” the simple answer is yes.
Canned tuna in appropriate portions, and preferably skipjack or albacore rather than the larger tuna fish, can be a healthy protein-rich snack for your dog. However, look for tuna in water rather than oil.
Some owners like to offer their dogs the water that the canned tuna is packed in. If you decide to do this, first be sure the tuna does not have any added salt.
Tuna lives in saltwater, so it is only natural it may have higher sodium levels than freshwater fish.
But you can still get low sodium canned tuna fish. Look for the phrase “no salt added.”
Can Dogs Eat Raw Tuna?
Can dogs have tuna that hasn’t been cooked and canned?
Sushi is very popular today, and it is also delicious. And you can be sure that if you left a tasty raw tuna filet on your counter and your pup spied it, it would likely go “down the hatch” before you could blink twice!
But feeding your dog raw tuna – or raw fish of any kind, for that matter – is not the safest choice. This is because raw fish can carry bacteria and parasites that may be damaging once consumed.
Freshwater salmon is a perfect example. Some freshwater salmon carry bacteria that can infect your dog with salmon poisoning, a canine condition that is typically fatal within two weeks unless treated.
While there is no direct parallel with tuna, this simply illustrates one of the known dangers of eating raw fish.
Another reason not to feed raw fish to your dog is because raw fish contains the enzyme thiaminase. Thiaminase will make any thiamin (vitamin B1) your dog takes in inactive. But when you cook the tuna, the thiaminase is destroyed.
Since your dog will probably like his tuna treat just as much if you cook it first, overall it is much safer if you feed your dog cooked tuna rather than raw tuna.
Can Dogs Eat Tuna With Mayo?
Generally speaking, dogs can eat tuna with mayonnaise. In fact, they may seem to prefer a nice tuna fish sandwich, especially if that’s what you’re currently eating!
However, a note of caution is involved when it comes to feeding your dog too much mayonnaise. Just as is the case with humans, too much mayo can just be more fat than is good for us.
Fats are an important part of a dog’s diet. But both too much and too little can cause health issues.
If you’re going to feed your dog a tuna fish sandwich, make sure to only do it every now and then, rather than making mayo or tuna a significant portion of his diet.
Can Puppies Eat Tuna Fish?
The jury is still out on whether it is okay to feed tuna to puppies. But personally, we think it’s worth giving it a miss.
While tuna does have some beneficial nutrients as well as the always helpful omega-3 fatty acids, there is also the mercury content to consider.
Plus, your pup’s complete food will be giving him all the nutrients that he needs already.
Your puppy’s entire digestive and gastrointestinal system is still developing through the first year of life.
It’s best to avoid potential upsets, and stick to their complete formula during these important early months.
Can Tuna Treat Sensitive Stomachs In Dogs?
As we mentioned above, tuna is sometimes found in commercial dog foods. These can be aimed at helping dogs with sensitive stomachs who have difficulty processing other types of protein.
Can dogs have tuna and see their stomach problems disappear?
Well, each dog is an individual. And food sensitivities and intolerance may differ from animal to animal. So there’s no hard and fast rule on this.
However, according to pet nutritionist David Southey, who is an advocate of fish for dogs, fish can help to counter sensitivities due to lower fat levels. This may make it easier to digest.
On the other hand, that doesn’t mean that your dog’s sensitivities have simply gone away. It just means that you may be able to keep them somewhat under control.
With any new food, it’s always best to feed your dog only a little at first. Wait to see the reaction, if any, before you let your pup eat more.
Should I Give My Dog Tuna?
There is a big difference between feeding your dog tuna occasionally as a treat and making it a staple of her diet. In general, if you’re wondering, “Can I feed my dog tuna?” it should be as safe for your dog as it is for you, provided you follow healthy portion guidelines.
Health guidelines typically suggest limiting your tuna portion based on how much you weigh. This handy formula works just as well for dogs as it does for people! For example, let’s say your dog weighs 20 pounds.
In this case, she shouldn’t consume more than one whole can of tuna more than every 3 weeks (chunk light) or every 10 weeks (white albacore).
If your dog weighs 40 pounds, he can have one can of chunk light tuna every 9 days, and one can of white albacore tuna every 4 weeks.
For pups that weigh 90 pounds, it is okay to consume one can of chunk light tuna every 5 days and one can of white albacore tuna every 2 weeks.
And if your pooch weighs 150 pounds, he can have a can of chunk light tuna every 3 days and a can of white albacore tuna every 9 days.
This gives you a good range of options for adding canned tuna into your dog’s treat rotation.
How To Prepare Tuna For Dogs
If you’re anxious to try and see if your dog likes tuna, it’s definitely a good idea to take it slowly.
Either cook and debone the tuna, or open a can of tuna packed in water. Give him a little at a time and wait to see how he reacts.
Alternatively, if your dog has a sensitive stomach and you’re interested in finding a food that he likes, look for dog foods which include tuna or other fish as an ingredient, rather than poultry.
Again, remember to take it slowly, to make sure that your dog reacts well to tuna and to any other new ingredients.
Alternatives To Tuna For Dogs
If you want to give your dog some new type of protein, but the worries over mercury levels are too concerning, there are certainly other options out there!
Take a look at these possible ingredients for your pup’s food, or simply as a treat.
Can Dogs Eat Tuna Fish Summary
As long as you are careful, offering your dog the occasional tuna treat should be okay.
If you decide to feed your dog tuna, make sure it is cooked tuna, made from skipjack or albacore.
Also ensure there is no salt added.
Only give your dog tuna in an appropriate portion, relative to your dog’s weight.
This will keep the risk of mercury poisoning low while providing your dog with the benefits of tuna’s vitamin and mineral content, plus the omega-3 fatty acids.
References And Further Reading
- Heinze, C, 2018, The Skinny On Fat, Cummings Veterinary Medical Center, Tufts University
- 2017, Fish Based Pet Food May Help Sensitive Stomachs, Pet Food Industry
- FDA, “Mercury Levels in Commercial Fish and Shellfish” U.S. Food and Drug Administration (FDA), 2017.
- Sheer, R., et al, “How Does Mercury Get Into Fish?” Scientific American, 2018.
- Ware, M., RDN, LD, “How Often Should I Eat Tuna?” Medical News Today, 2016.
- Mataljan, G., “Tuna: Nutritional Content,” World’s Healthiest Foods, 2018.
- Hoggan, S., “Salmon Poisoning” The College of Veterinary Medicine at Washington State University, 2018.
- Pendergrass, J., DVM, “Mercury in Dog and Cat Foods: Cause for Concern?” American Veterinarian, 2016.
This article has been extensively revised and updated for 2019.